Hydraulic system for a power operated apparatus

ABSTRACT

A hydraulic system for power-operated apparatus such as a back hoe, crane or shovel. The apparatus includes a boom which is pivotally connected to a supporting structure and a hydraulically operated working member such as a cylinder or motor is located on the boom. The hydraulic system utilized to operate the working member is carried entirely by the boom and includes a fluid reservoir and a pump. The reservoir is located within the inner end of the boom while the pump has an input shaft disposed in axial alignment with the pivotal connection between the boom and the supporting structure. A driving source on the supporting structure is operably connected to the pump shaft to operate the pump and supply fluid through the hydraulic system to the working member.

Inventor John P. Waite Menomonee Falls, Wis.

Appl. No. 824,938

Filed May 15, 1969 Patented Jan. 19, 1971 Assignee J. P. Waite, Inc.

Milwaukee, Wis. a corporation of Wisconsin US. Cl.... 214/138 Int. Cl E02f 3/75 Field of Search 214/138,

131, 132, 133, 134, 135, 136, 137, 140; 2l2/(Inquired); 37/103 [56] References Cited 7 UNITED STATES PATENTS 2,612,113 9/1952 Albright 214/131x Primary Examiner-Hugo O. Schulz Att0rneyAndrus, Sceales, Starke and Sawall ABSTRACT: A hydraulic system for power-operated apparatus such as a back hoe, crane or shovel The apparatus includes a boom which is pivotally connected to a supporting structure and a hydraulically operated working member such as a cylinder or motor is located on the boom. The hydraulic system utilized to operate the working member is carried entirely by the boom and includes a fluid reservoir and a pump. The reservoir is located within the inner end of the boom while the pump has an input shaft disposed in axial alignment with the pivotal connection between the boom and the supporting structure. A driving source on the supporting structure is operably connected to the pump shaft to operate the pump and supply fluid through the hydraulic system to the working member.

' The invention relates to a hydraulic system to be utilized with power operated equipment such as, a backhoe, shovel,

crane, or the like. v I

A conventional backhoe or shovel; may include one or more 7 hydraulically operatedworking members such as hydraulic cylinders which are located on theboom. For example, a

- hydraulic cylinder may be employed topivot the bucket with respect to the dipper stick, or a hydraulic cylinder may be employed to pivot the dipper stick with respect to the boom. In

the conventional construction the components of the hydraulic system such as the fluid reservoir, the pump, and the valve block are located on the cab of supporting structure and the hydraulic linesextend from the cab along the boom to the cylinder or cylinders. In some instances there is very little space on the cab to mount the hydraulic system with the result that the components of the hydraulic system must be located in available, yet often fundesirable positions and this com plicates the piping forthe hydraulic system.

' Moreover, mounting the; hydraulic system onthe cab-results in an increased generation of heat in the cab which-is objectionable in many cases to the operator.

further. disadvantageof mounting the hydraulic system'on the cab is that itincreases the length of the hydraulic lines to the cylinders, which arelocated on the'outer end of the boom,

creased. It is recognized that heated oil does not perform as efficiently as cooler oil, and in some conventional installations,

The hydraulic system of the invention can be readily adapted to both existing equipment as well as new equipment. In connection with existing equipment, the reservoir, pump, and valve block of the hydraulic system can be readilyassembled on'the boom without any alteration or modification oithe existing components of the boom.

Other objects and advantages will appears in the course of the following description. V P

ln thedrawings: I

FIG. lis a side elevation of a backhoe incorporating the hydraulic system of the invention; and

FIG. 2 is a fragmentary plan view with parts broken away in section of the boom and the cab.

. The drawings illustrate a poweroperated backhoe or drag shovel comprising a cab l which houses a drive mechanism and is mounted for rotation on crawlers or treads 2. Aboom 3 is'pivotally connected to the cab l, and a dipper stick 4 is pivotally connected to the outer end of the boom.

Pivotally mounted on the lower end of the dipper stick is a dipper 5 and the dipper is adapted to be pivoted with respect to the dipper stick by a hydraulic cylinder 6. The upper end of and therefore the heatgenerated by the line friction is-inoil coolers are incorporatedin the hydraulicsystem to counter 7 balance the heat generated by linefriction.

Frequently an operator may wish to change from a backhoe I v boom to a crane boom, or vice versa. with the conventional machine in which the hydraulic system is located on the cab it is necessary to disconnect and draintthe hydraulic lines in order to change from 'one boom to another.

The present invention is directed to'a hydraulic system to be utilized with. a power. operated apparatus such as" a backhoe,

1 crane or shovel. According'to the invention, the apparatus in-.

cludes a boom which is'pivotally connected about a horizontal axis to a cab or supporting structure. One or more hydraulically operated working'memberssuch as hydraulic cylinders are located on the' boom and the hydraulic system which is utilized to operate the cylinder is carried entirely on the boom. More specifically,"'the hydraulic system-includes a reservoir which is located within theinner end of the boom, and a pump is carried by the boom and'has an input drive shaft disposed in alignment with the pivotal connection between the boom and r the cab. A driving source located on the. cab is operably connected to the pump shaft to operate the pump and supply hydraulic fluid through the system to the cylinders located on the boom.

With the present invention all of the components of the hydraulic system such as the reservoir, pump, and valve block are located on the boom and no space is required for the hydraulic system in the cab. This has the additional advantage in'that all of the components of the hydraulic system can be located immediately adjacent to each other so that the piping and other connections are simplified and the overall cost of in- I stallation is reduced.

As a further advantage of mounting the hydraulic system on the boom, the fluid can be exhausted from the cylinders to the reservoirs more quickly than in a system where the reservoir is located on the cab. This isimportant to the speed of operation, and also prevents excessive heating of the oil due to line friction and thereby improves the performance of the system.

As all of the hydraulic components are mounted on the boom,.the boom can be disassembled from the cab without disconnecting the hydraulic system.'This enables the operator to readily substitute a crane boom for a backhoe or'shovel boom without modification or disassembly of the hydraulic system. t i

the cylinder 6 is pivotally connected to a pair of lung 7 which are secured to the dipper stick 4 and the piston rod or ram 8 of and contraction of the piston rod 8 will cause the dipper S to pivot with respect to the dipper stick4 a The dipper stick 4 can be pivoted with by a mechanism similar to that described in US. Pat. No. 3,319,812 of the'same inventor. In this constructioma pair of arms 10 are pivotally connected to the upper end of the dipper stick 4 and a second pair of arms 1'! are-pivotally connected to the boom 3. The adjacent ends of the'same inventor. In this construction, a pair of arms vl0 are pivotally connected to the upper end of the dipper stick 4'and a second pair of arms 1! are pivotally connected to the boom 3. The adjacent ends of the arms 10 and 11 are pivotally mounted on a shaft 12. The 7 ends of thearms 10 as well as the ends of the arms 11 straddle asheave 13 which is rotatable mounted on the shaft 12.

in addition to sheave 13,a second sheave "is mounted for rotation on the upper end of a mast 15, which is pivotally connected to the cab l. A hoist line cable 16 whichissecured to a drum [7 passes over sheaves l4 and 13V and is dead ended on the mast 15. By retrieving the cable 16, the sheave T3 is moved toward the sheave 14 thereby pivoting the boom 3 upwardly about the forward portion of the cab, while letting out the cable 16 enables the boom to pivot downwardly with respect to the cab. Y

A sheaving arrangement is employed to supply a force through the arms 10 and 11 to the upper end of the dipper stick to pivot the dipper stick 4 about 'the boom 3 in the manner as disclosed in US. Pat. No. 3,3 l 9,8l2. The sheaving arrangementincludes a pair of sheaveslfl mounted on a shaft 19 which is secured between brackets 20 attached to the boom. in addition to the sheaves 18, a second pair of sheaves 21 are mounted on the shaft 12 on opposite sides of the arm 11. A drag cable 22 secured to drum passes over a sheave 24 on boom 3 and is reeved around the sheaves l8 and 21 and is dead ended on the bracket 20. By. retreiving the drag cable 22, the sheaves 21 are moved inwardly toward the sheaves 18 on the boom, with the result that the arms 10 and 11 move to an extended position away from the machine and move the dipper inwardly toward the machine. Conversely, by letting out on the cable 22'the sheaves 21 move away from sheaves '18 causing the arms 11 and 12 to scissor or move toa lugs 26 on boom 3 by pins 27. This pivotal connection enables the boom to be pivoted in a vertical plane about the horizontal axis through the pins 27.

respect'to'the boom According to the invention, the hydraulic system for operating the cylinder 6 is carried entirely on the boom 3. More specifically, a reservoir 28 is located within the inner end of the boom. The reservoir 28 can be a separate tank located within the boom, or alternately the walls of the boom, in combination with transverse walls, can be used to define the reser- VOll'.

A pump 29 is mounted on a mounting plate 30 extending from the inner end of the boom. and the drive shaft 31 for the pump 29 isjournaled within a bearing assembly 32 attached to the plate 30. As shown in FIG. 2, the axis of the drive shaft 31 is disposed in axial alignment with the pins 27 which pivotally connect the boom to the cab.

To drive the shaft 31, a sprocket 33 is secured to the shaft and is connected by an endless drive member such as a chain 34 to sprocket 35 on shaft 36 which is journaled for rotation by bearings 37 on the cab 1. Shaft 36 also carries a pinion 38 which is driven by a gear 39 mounted on the shaft 40 of drum 19. With this drive connection, rotation of the shaft 40 acts to drive the pump shaft 31 to operate the pump 29. As the drive shaft 31 for the pump is located on the pivotal axis between the boom 3 and the supporting structure, the boom can be raised and lowered without interfering with the drive connection to the pump.

The hydraulic system also includes a conventional valve block 41 which is mounted on the boom adjacent the pump 29. A pressure line 42 connects the discharge side of the pump to the valve block 41, and a suction line 43 connects the suction side of the pump to the fluid reservoir 28. In addition, a supply line 44 is connected from the valve block to one end of the cylinder 6, and a return line 45 is connected from the opposite end of the cylinder to the valve block. The hydraulic fluid is returned from the valve block 41 to the reservoir through line 46. The valving arrangement employed to deliver the hydraulic fluid to the hydraulic cylinder 6 is conventional and in itself forms no part of the present invention.

With the hydraulic system of the invention, all of the components such as the pump, the fluid reservoir, and the valve block, as well as the hydraulic lines, are all located on the boom. Moreover, these elements are all located immediately adjacent to each other so that the piping between the pump, reservoir and valve block is minimized.

Mounting the entire hydraulic system on the boom has an advantage in that the boom can be disassembled from the cab without disconnecting or draining the hydraulic lines. This enables the operator to readily substitute a crane boom for the backhoe, or vice verse, without altering or disassembling the hydraulic system.

By locating the hydraulic system on the boom, the hydraulic lines to the cylinder 6 are reduced in length over a conventional system in which the hydraulic system is located on the cab. By reducing the length of the hydraulic lines the amount of heat generated by line friction is correspondingly reduced and this provides more efficient performance as cooler oil will perform more effectively than heated oil.

The invention can be applied either to new or existing construction equipment. When applied to existing equipment, the entire hydraulic system can be mounted on the boom without any substantial alteration or modification of the boom or other components.

While the above invention hasbeen directed to a hydraulic system for supplying fluid to the cylinder 6, it is contemplated that the boom may carry one or more hydraulically operated working members such as cylinders, hydraulic motors. or the like.

I claim:

1. ln a power-operated apparatusj a supporting structure, a boom, means for pivotally connecting the boom to the supporting structure about a horizontal axis, a hydraulically operated element mounted on the boom, a hydraulic system mounted on the boom and including a reservoir and a pump, said pump having a drive shaft disposed in alignment with said horizontal axis, power means mounted on said supportin structure, and drive means connecting said power means an said drive shaft.

2. The apparatus of claim 1, wherein said reservoir is located within the inner end of the boom.

3. The apparatus of claim 1, wherein said hydraulic system includes valve means mounted on the boom.

4. in a power-operated apparatus, a supporting structure, a boom, means for pivotally connecting the boom to the supporting structure about a horizontal axis, at least one hydraulically operated element carried by the boom, a hydraulic system operably connected to said hydraulically operated element and mounted on said boom, said hydraulic system including a fluid reservoir located at the inner end of said boom and including a pump mounted on the inner end of the boom, said pump including a drive shaft disposed in axial alignment with said horizontal axis, said hydraulic system also including valve means mounted on the boom adjacent the reservoir, power means disposed on the supporting structure, and drive means operably connecting the power means with said drive shaft to thereby operate said pump and deliver hydraulic fluid through said hydraulic system.

5. The apparatus of claim 4, wherein the reservoir is located within the inner end of the boom and said valve means is located on the outer surface of said boom.

6. The apparatus of claim 4, wherein said power means includes a gear train, and said drive means includes an endless drive member connecting said gear train and said shaft.

7. The apparatus of claim 4, wherein said hydraulically operated element comprises a hydraulic cylinder and said hydraulic system includes a fluid supply line connecting one end of the cylinder to said reservoir and a fluid return line connecting the opposite end of the cylinder to said reservoir.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,556,322 Dated January 19, 1971 Inventor(s) JOHN P. WAITE It is certified that error appears in the above-identified patent: and that said Letters Patent are hereby corrected as shown below:

Column 2, line 23, Cancel "lung" and substutute therefor ---lugs--, Column 2, line 34, Cancel "The adjacent end of the same inventor. In this", Column 2 line 35, Cancel "constructi a pair of arms 10 are pivotally connected to the", Column 2, line 36, Cancel "upper end of the dipperstick 4 and a second pair of arms 11'', Column 2, line 37, Cancel "are pivotally con nected to the boom 3.", Column 3, line 47, Cancel "verse" and substitute therefor ---versa--- Signed and sealed this 13th day of July 1971.

(SEAL) Attest:

EDWARD M.FIETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer 7 Commissioner of Patents 

1. In a power-operated apparatus, a supporting structure, a boom, means for pivotally connecting the boom to the supporting structure about a horizontal axis, a hydraulically operated element mounted on the boom, a hydraulic system mounted on the boom and including a reservoir and a pump, said pump having a drive shaft disposed in alignment with said horizontal axis, power means mounted on said supporting structure, and drive means connecting said power means and said drive shaft.
 2. The apparatus of claim 1, wherein said reservoir is located within the inner end of the boom.
 3. The apparatus of claim 1, wherein said hydraulic system includes valve means mounted on the boom.
 4. In a power-operated apparatus, a supporting structure, a boom, means for pivotally connecting the boom to the supporting structure about a horizontal axis, at least one hydraulically operated element carried by the boom, a hydraulic system operably connected to said hydraulically operated element and mounted on said boom, said hydraulic system including a fluid reservoir located at the inner end of said boom and including a pump mounted on the inner end of the boom, said pump including a drive shaft disposed in axial alignment with said horizontal axis, said hydraulic system also including valve means mounted on the boom adjacent the reservoir, power means disposed on the supporting structure, and drive means operably connecting the power means with said drive shaft to thereby operate said pump and deliver hydraulic fluid through said hydraulic system.
 5. The apparatus of claim 4, wherein the reservoir is located within the inner end of the boom and said valve means is located on the outer surface of said boom.
 6. The apparatus of claim 4, wherein said power means includes a gear train, and said drive means includes an endless drive member connecting said gear train and said shaft.
 7. The apparatus of claim 4, wherein said hydraulically operated element comprises a hydraulic cylinder and said hydraulic system includes a fluid supply line connecting one end of the cylinder to said reservoir and a fluid return line connecting the opposite end of the cylinder to said reservoir. 